Electric generator drive mechanism

ABSTRACT

Device for driving the rotor of an electric generator which includes a spring biased drive member operatively connected to the generator rotor. The biasing spring is normally not effective to bias the drive member and is rendered effective during the process of setting the drive members in motion. The output of the generator may supply power to a camera flash lamp circuit and/or exposure control mechanism.

United States Patent [151 3,703,132 [451 Nov. 21, 1972 Beach [541ELECTRIC GENERATOR DRIVE MECHANISM [72] Inventor: David E. Beach,Penfield, N.Y.

[7 3] Assignee: Eastman Kodak Company,

Rochester, N.Y.

[22] Filed: Sept. 29, I969 21 Appl. No.: 861,916

[521 US. Cl ..'..9s/11.s [51] Int. Cl. ..G03b 9/70 [58] Field ofSearch..; ..95/11, 11.5

[56] References Cited UNITED STATES PATENTS 2,490,225 12/1949 McGall..95/1 1.5 2,542,164 2/1951 Tatr0....- ..95/1l.5 2,976,398 3/1961 McKee..240/1.3

3,063,352 11/1962 Engelsmann ..95/10 C 3,211,069 10/1965 Rixton..95/11.5 2,328,831 9/1943 Mendelsohn ..95/1 1.5 2,972,937 2/1961 Suits..95/11.5 2,576,934 12/1951 Grier .'......95/l 1.5 X 2,299,497 10/ l 942Rosenthal ..95/1 1.5

Primary Examiner-John M. l-loran Attorney-Robert W. Hampton and MiltonS. Sales [5 7 ABSTRACT Device for driving the rotor of an electricgenerator which includes a spring biased drive member operativelyconnected to the generator rotor. The biasing spring is normally noteffective to bias the drive member and is rendered effective during theprocess of setting the drive members in motion. The output of thegenerator may supply power to a camera flash lamp circuit and/orexposure control mechanism.

5 Claims, 2 Drawing Figures ELECTRIC PATENTED I973 3.703.132

TRIGGER DAVID E. BEACH INVENTOR.

BY 7% W WM M AT TORNE YS .l 1 ELECTRIC GENERATOR DRIVE MECHANISMCROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to drive mechanisms forelectric generators and is particularly but not exclusively suited foruse with generators of the type used in photographic apparatus such ascameras.

2. Description of the Prior Art Photographic apparatus such as camerasthat employ electric generators are known in the art. Such apparatuscommonly employ a spring biased driving member to rapidly rotate thegenerator armature. It is further known to set the drive spring in itsforce apply: ing state by a mechanism such as the film advancing linkageor a manually operated crank. Once the spring is set in its forceapplying state, the member is set in motion by releasing a latch,permitting the armaturedriving device to move rapidly under theinfluence of the spring. After the generator has supplied sufficientpower to operate a flash lamp, the camera shutter is automaticallyreleased. Such devices are shown in U.S. Pat. No. 2,322,067 to Ernest V.Soreny ,entitled FLASHLIGHT SYNCHRONIZING DEVICE and published GermanApplication No. 1,149,607 to Hans Wiener ct al.

Where the spring for biasing the generator drive member is set in itsforce applying state by film winding apparatus, the return stroke of theshutter release lever, etc., certain problems arise. For instance,reliance on the film winding mechanism to reset the system wouldpreclude intentional double exposures. If the return stroke of theshutter release lever were relied upon to reset the system, the shutterrelease return spring would necessarily have a large spring constantrequiring considerable force to activate the camera. This is aggravatedby the fact that the point of greatest resistance to resetting would bereached when the release lever return spring was substantially fullyextended.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improved mechanism for driving an electric generator by aspring biased member wherein the drive spring is set to a force applyingstate during movement of a device movable for setting the member inmotion.

In accordance with a preferred embodiment of the invention, a movablymounted generator drive sector or member has gear teeth which mesh witha pinion fixed to a generator armature. The drive member is powered by aspring which is set to a force applying state during the unlatchingoperation of the drive member, whereupon the drive member moves througha path to drive the generator. The movement of the drive member causesthe closing of a switch in,the flash lamp circuit, the setting of anexposure control mechanism and/or the tripping of the shutter drivemechanism. r g

The invention, and its objects and advantages will become more apparentin the detailed description of the preferred embodiments describedbelow.

BRIEF DESCRIPTION OFTHE DRAWING In the detailed description of thepreferred embodiments of the invention presented below, reference ismade to the accompanying drawings, in which:

FIG. 1 is a schematic view of one embodiment of the present invention;and

FIG. 2 is a schematic view of a second embodiment of the invention.

THE PREFERRED EMBODIMENT OF THE INVENTION Because cameras are wellknown, the present description will be directed in particular toelements forming part of, or cooperating more directly with, apparatusin accordance with the present invention. It is to be understood thatcamera elements not specifically shown or described may take variousforms well known to those skilled in the art.

Referring to FIG. 1, there is shown a camera flash system in which theelectrical power to ignite the flash lamp is supplied by a generatorwhich is driven by a mechanical linkage system associated with theshutter release mechanism.

A shutter release member comprising a slide or lever 10 is mounted in acamera casing 11 for vertical movement. A spring 12 biases slide 10towards its raised position. A lug 14 extends from slide 10 and carriesa post 16.

A generator drive sector 18 is mounted for rotation about a pivot 20adjacent release slide 10. A leg 22 carried by drive sector 18 extendstowardslide 10 above post 16. The drive sector is provided with anarcuate edge having gear teeth 24 extending along a portion thereof anda void 26 along a second portion.

A latch member 28 is rotatably carried by pivot 30 for cooperation witha lug 32 on drive sector 18 and is biased for rotation in a clockwisedirection by spring 34. A spring 36 is carried by pivot 20 and abutspost 16 at one end and a post 38 on drive sector 18 at the other.

Drive sector 18 is'positioned to engage a lug 39 on a pivotally mountedlatch 42 which is normally biased for rotation in a counterclockwisedirection about a pivot 41 by a spring 44. In the position shown in FIG.1, latch 42 normally holds a shutter drive lever 40 to the left againstthe bias of a spring 46.

The camera lens 48 is provided with a conventional shutter mechanism 50which carries a projection 52 lying in the path of shutter drive lever40. The shutter mechanism is pivotally mounted on the camera housing at54.

A generator 56 having a movable part or rotor such as an armature, notshown and a stator, carries a pinion 58 which is positioned to cooperatewith gear teeth 24 on drive sector 18. A capacitor 60 is connected overthe windings of generator 56 and is electrically charged when thearmature is rotated by sector 18. A diode 62 is provided to prevent thecapacitor from discharging through the generator winding. A flashattachment having a bulb 64 is connected in parallel with capacitor 60,

theelectrical connection including a switch 66 in the flash attachmentcircuit and positioned adjacent shutter 50 to be closed when the shutteris opened. An exposure control circuit may also be powered by generator56 as disclosed in my copending application Ser. No. 861,942, filedconcurrently herewith.

In operation, spring 36 is only slightly tensioned when release slide isin its raised position. As the slide is depressed, post 16m0vesdownwardly to tension spring 36. As this is happening, latch member 28prevents movement of generator drive sector 18. When release slide 10has been depressed to a point in which lug 14 makes contact with latchmember 28, further depression of the slide will pivot the latch memberin a counterclockwise direction to release drive sector 18 forcounterclockwise rotation induced by spring 36. Rotation of drive sector18 drives generator 56 through gear teeth 24 and pinion 58. Void 26 ondrive sector 18 permits continued rotation of pinion 58 under theinfluence of the momentum of the armature for a limited time after fulltravel of the drive sector. When generator drive sector 18 approachesits end of travel, it abuts latch 42 to release shutter drive lever 40.Rightward travel of lever 40 opens shutter 50 and closes switch 66 tofire flash lamp 64 by discharging capacitor 60.

To return the mechanism to its cocked position, the operator releasesslide 10 which is then raised by spring 12. Post 16 in cooperation withleg 22 rotates drive sector 18 in a clockwise direction until it islatched by member 28. Shutter drive member 40 may be returned to theposition illustrated by conventional cocking means, not shown.

FIG. 2 shows an embodimentof the present invention which is adapted toprovide a low-light signal to indicate insufficient scene brightness,set an exposure control mechanism or fire a flash lamp.

A shutter release slide or lever 110 is mounted for movement between araised, start position A; a partially depressed, generator trip positionB and a fully depressed, shutter trip position C. Release slide 110 isbiased upwardly by spring 112 and is provided with a leaf spring 114which increases the back pressure felt by the operator when the slidereaches its intermediate position B. Release slide 110 carries one leg116 of a pivotally mounted lever 118 between a pair of lugs 120 and 122.The other leg of lever 118 is attached through spring 124 to a generatordrive slide 126. Slide 126 can be considered a drive's ector as in FIG.1 having infinite radius and is provided with teeth 128 which mesh witha pinion 130 of a generator 132. Slide 126 is normally prevented fromrightward movement by a latch 134.

Generator 132 is electrically connected to a capacitor 136 in parallelwith a flash attachment 138 and a switch 140 associated with the shuttermechanism. For non-flash pictures, a solenoid coil 142 in series with anelectronic trigger device 144 are connected across capacitor 136 andwould be put into the circuit by closing a switch 146.

A control member 148 is positioned above drive slide 126 and is latchedin the position shown against the biasing force of a spring 150 by apivoted, spring biased lever 152. Movement of control member 148 isretarded by a damping device 154.

A pair of lugs 156 and 158 are carried by control member 148. The secondlug, 158, is engaged by a projection 160- on a lens and photocelldiaphragm member 162, the diaphragm member being urged in a direction ofrotation about pivot 164 by a spring 166. Diaphragm member 162 isprovided with a pair of tapered apertures 168 and 170 which overlie lens172 and photocell 174, respectively, thephotocell being part ofelectronic trigger 144. The periphery of diaphragm member 162 isprovided with a plurality of ratchet notches 176 and with a low-lightflag 178 which cooperates with a viewfinder 180 in a manner to bedescribed. A diaphragm stop lever 182 is carried adjacent solenoid 142and ratchet notches 176 and abuts lug 156 on control member 148.

Two levers 184 and 186 have lower legs lying in the paths of the upperleg of lever 118 and control member 148, respectively. The other legs oflevers 184 and 186 engage a spring biased shutter drive lever 187.

In the cocked position as shown, spring 124 is only slightly tensioned.As shutter release slide 110 is depressed, lever 118 rotates in aclockwise direction to tension spring 124. During this time, latch 134prevents generator drive slide 126 from moving. As release slide 110reaches its position B, lever 118 engages latch 134 to rotate it in acounter-clockwise direction and release drive slide 126 for rightwardmovement. When generator drive slide 126 has reached the end of itstravel, capacitor 136 has been charged with electrical energy bygenerator 132, and latching lever 152 is rotated by the drive slide torelease control member 148; Because of the absence of teeth on the leftside of slide 126, the generator armature will continue to rotate due toinertia.

Control member 148 has now been unlatched and moves under the'load ofspring 150 at a rate controlled by damping device' 154. Lens andphotocell diaphragm member 162 follows the motion of control member 148to uncover lens 172 and. photocell 174 at predetermined rates. If thelight energy falling on photocell 174 from the scene being photographedreaches a predetermined value due to the uncovering of the cell byaperture 170, the electronic trigger 144 switches on solenoid 142 todischarge the remaining energy in capacitor 136. Solenoid 142 then pullsstop lever 182 to the right (lug 156 having been displaced by rightwardmovement of control member 148) to latch diaphragm member 162 againstfurther movement. This operation correctly sets the exposure for theexisting amount of scene brightness.

Control member 148 continues its travel to disengage latch lever 186from the path of shutter drive lever 187. If shutter release slide 110has been depressed to position C, latch lever 184 has already beenpivoted out of the path of shutter drive lever 187 and the shutter willbe tripped. If release slide 110 has only been depressed to position B,the shutter will not trip due its engagement by latch lever 184. In thelatter case, the picture may be taken by depressing release slide 110 toposition C or the mechanism may be returned to the position shown inFIG. 2 without exposing the film by releasing slide 110.

However, if the scene brightness is below the lowlight capacity of thecamera, the energy falling on photocell 174 will not reach thepredetermined value needed to tire solenoid 142 even at maximum rotationof diaphragm member 162, and stop lever 182 would not be pulled in bythe solenoid. Diaphragm member 162 will, therefore, continue to rotateto its limit of travel and low-light flag 178 will appear in viewfinder180. Alternatively, an indicator light may be substituted for low-lightflag 178 with the diaphragm member operating a switch to connectcapacitor 136 to the light. Such systemsare well known in the art andhave not been illustrated. If release slide 110 is not pushed beyondposition B, the shutter will not be tripped when control member 148reaches the end of its travel as explained above. Release slide 110 maythen be returned to its starting position A and an exposure will nothave been wasted. If the photographer still desires to take the picture,he may do so by pushing shutter release slide 110 to the C position.Means can be provided for coupling switch 140 to release slide 110during the low-light condition, so that switch 140 is closed upon thelatter movement of slide 110 to the C position.

Whenever shutter release'slide 110 is released to return to its startingposition, the camera apparatus is reset by virtue of lever 118 engaginga lug-188 on generator drive slide 126, thereby pushing the slide to itslatched position. A lug 190: on slide 126 then engages control member148 to return it to its starting position where it is latched by lever152. Shutter drive lever 187 is not reset by this mechanism and it canbe moved to the left by known methods including the film advancingmechanism, the up-stroke of release slide 110 or a shutter cockinglever. Alternatively,'means may be provided on control member 148 topull lever 187 back to the position shown as control member 148 iscocked.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood thatvariationsand modifications can be effected within the spirit and scopeof the invention.

lclaim:

1. In a camera having a shutter operatable for making a photographicexposure, a device for driving an electric generator of the type havinga stator and a rotor mounted therein for relatively free rotation for aI limited duration, said device comprising:

a. a member movable'from an initial position through a path for drivingthe generator rotor, said movable member including means for drivinglycoupling said movable member to said generator rotor during only a firstportion of the movement of said member through said path so that saidmovable member is not coupled to said generator rotor during the secondportion of the movement of said member through said path, whereby saidgenerator rotor can continue movement independent of said movable memberafter said member has moved through said first portion of said path;

. releasable means for preventing movement of said member;

0. means movable from a first position to a second position foroperating said shutter and for releasing said movement preventing means,thereby rendering said movable member free to move;

6 d. means for transmitting force to said, movable member for impartingmovement thereto, said force transmitting means being alternativelyplaceable in a de-energized condition wherein said means is incapable oftransmitting said force to said movable member, and an energizedcondition wherein said means is capable of transmitting said force tosaid movable member, said force trans mitting means assuming saidtie-energized condition when said releasing means is in said firstposition; and

e. means for placing said force transmitting means in saidenergizedcondition in response to movement of said releasing means from saidfirst position towards said second position.

2. A device according to claim 1 further comprising means for movingsaid movable member to said initial position in response to movement ofsaid releasing means to said first position.

3. A camera having a movable shutter and electrically energizable meansfor facilitating the making of an exposure, said camera comprising:

a. an electric generator including a rotor mounted for rotation throughat least one complete revolution;

b. a member movable from an initial position through a path c. means fordrivingly coupling said movable member to said generator rotor duringonly the first portion of the movement of said member through said pathto drive the generator and for decoupling said member and said rotorduring the second portion of the movement of said member through saidpath;

d. a release lever movable between an initial and a release position;

e. spring means for biasing said movable member for movement throughsaid path;

f. a first latch releasably retaining said movable member in saidinitial position;

g. means for releasing said first latch in response to movement of saidrelease lever to said release position to release said movable member,thereby allowing said spring means to move said movable member throughsaid path to drive said generator;

h. means for storing electrical energy produced by said generator priorto the exposure;

i. a shutter drive lever displaceable between cocked and uncockedpositions for moving the shutter and for connecting said energy storagemeans to the exposure facilitating means;

j. means biasing said shutter drive lever for displacement from saidcocked position to said uncocked position;

. a second latch releasably holding said shutter drive lever in saidcocked position; and

. means disposed for engagement with said movable member during thesecond portion of the movement of said member through said path forreleasing said second latch, whereby said shutter drive lever isdisplaced to said second uncooked position to substantiallysimultaneously move the shutter and to cause energization of saidexposure facilitating means.

4. A camera as defined in claim 3 wherein said energy storage meanscomprises:

a. an electrical capacitor for storing energy produced by saidgenerator;

b. a normally open switch and a flash lamp receptacle connnected inseries across said capacitor, said switch being responsive to openingmovement of said shutter to connect said flash lamp receptacle to saidcapacitor.

5. In a camera having a shutter operatable for making a photographicexposure, and an electrically energizable exposure control mechanismincluding a movable first member for establishing an exposure parameter,means for moving the first member, and means positionable in response toscene illumination for limiting the amount of movement of the firstmember, the improvement comprising:

a. an electric generator for energizing the exposure control mechanism;

b. means movable between first and second positions for driving saidgenerator;

c. a release lever movable between an initial and a release position foroperating the shutter;

(1. spring means interconnecting said generator driving means and saidrelease lever for biassing said generator driving means for movement tosaid second position;

. means releasably restraining said generator driving means in saidfirst position;

. means for releasing said restraining means in response to movement ofsaid release lever to said release position to effect the movement ofsaid generator driving means to drive said generator; and

. a second member for releasably engaging the first

1. In a camera having a shutter operatable for making a photographicexPosure, a device for driving an electric generator of the type havinga stator and a rotor mounted therein for relatively free rotation for alimited duration, said device comprising: a. a member movable from aninitial position through a path for driving the generator rotor, saidmovable member including means for drivingly coupling said movablemember to said generator rotor during only a first portion of themovement of said member through said path so that said movable member isnot coupled to said generator rotor during the second portion of themovement of said member through said path, whereby said generator rotorcan continue movement independent of said movable member after saidmember has moved through said first portion of said path; b. releasablemeans for preventing movement of said member; c. means movable from afirst position to a second position for operating said shutter and forreleasing said movement preventing means, thereby rendering said movablemember free to move; d. means for transmitting force to said movablemember for imparting movement thereto, said force transmitting meansbeing alternatively placeable in a de-energized condition wherein saidmeans is incapable of transmitting said force to said movable member,and an energized condition wherein said means is capable of transmittingsaid force to said movable member, said force transmitting meansassuming said de-energized condition when said releasing means is insaid first position; and e. means for placing said force transmittingmeans in said energized condition in response to movement of saidreleasing means from said first position towards said secondposition.
 1. In a camera having a shutter operatable for making aphotographic exPosure, a device for driving an electric generator of thetype having a stator and a rotor mounted therein for relatively freerotation for a limited duration, said device comprising: a. a membermovable from an initial position through a path for driving thegenerator rotor, said movable member including means for drivinglycoupling said movable member to said generator rotor during only a firstportion of the movement of said member through said path so that saidmovable member is not coupled to said generator rotor during the secondportion of the movement of said member through said path, whereby saidgenerator rotor can continue movement independent of said movable memberafter said member has moved through said first portion of said path; b.releasable means for preventing movement of said member; c. meansmovable from a first position to a second position for operating saidshutter and for releasing said movement preventing means, therebyrendering said movable member free to move; d. means for transmittingforce to said movable member for imparting movement thereto, said forcetransmitting means being alternatively placeable in a de-energizedcondition wherein said means is incapable of transmitting said force tosaid movable member, and an energized condition wherein said means iscapable of transmitting said force to said movable member, said forcetransmitting means assuming said de-energized condition when saidreleasing means is in said first position; and e. means for placing saidforce transmitting means in said energized condition in response tomovement of said releasing means from said first position towards saidsecond position.
 2. A device according to claim 1 further comprisingmeans for moving said movable member to said initial position inresponse to movement of said releasing means to said first position. 3.A camera having a movable shutter and electrically energizable means forfacilitating the making of an exposure, said camera comprising: a. anelectric generator including a rotor mounted for rotation through atleast one complete revolution; b. a member movable from an initialposition through a path c. means for drivingly coupling said movablemember to said generator rotor during only the first portion of themovement of said member through said path to drive the generator and fordecoupling said member and said rotor during the second portion of themovement of said member through said path; d. a release lever movablebetween an initial and a release position; e. spring means for biasingsaid movable member for movement through said path; f. a first latchreleasably retaining said movable member in said initial position; g.means for releasing said first latch in response to movement of saidrelease lever to said release position to release said movable member,thereby allowing said spring means to move said movable member throughsaid path to drive said generator; h. means for storing electricalenergy produced by said generator prior to the exposure; i. a shutterdrive lever displaceable between cocked and uncocked positions formoving the shutter and for connecting said energy storage means to theexposure facilitating means; j. means biasing said shutter drive leverfor displacement from said cocked position to said uncocked position; k.a second latch releasably holding said shutter drive lever in saidcocked position; and l. means disposed for engagement with said movablemember during the second portion of the movement of said member throughsaid path for releasing said second latch, whereby said shutter drivelever is displaced to said second uncocked position to substantiallysimultaneously move the shutter and to cause energization of saidexposure facilitating means.
 4. A camera as defined in claim 3 whereinsaid energy storage means comprises: a. an electrical capacitor forstoring energy produced by said generator; b. a Normally open switch anda flash lamp receptacle connnected in series across said capacitor, saidswitch being responsive to opening movement of said shutter to connectsaid flash lamp receptacle to said capacitor.